Sports Injuries Lecture Week 7 - Muscle Strain Injuries

bethdrysdale94's version from 2017-01-16 19:52


Question Answer
What are the actions of skeletal muscle?Produce force and motion. primarily responsible for maintaining and changing posture and locomotion
What is a muscle strain?overstretching of the muscle which tears the muscle fibres, usually near muscle/tendinous joint.
When are you most likely to pull a muscle?during eccentric contraction
What are the three grades of muscle tear?Grade 1, damage, 2, partial tear, 3, complete tear
In what sports are muscle strains most common?Australian, American and British football, rugby and sprinting
What are the most common muscle strains?Hamstring (5-7 new injuries per club per season in aus), followed by groin, quads and calf
Hamstringsmost active during running and sprinting which is when they are injured
Quadsused to straighten the knee for running, kicking, jumping etc
Hip flexorshooting and striking
Hip adductorcommonly injured during turning activities eg side foot passing
What is the incidence and main inciting event for hamstring injuries?26% of track and field, 12-15% in other common sports. increasing in trend. high recurrence rate of up to 32%. In soccer, averaged 18 days of absence from training. no limb dominance
What is the mechanism of injury for hamstring strain?terminal swing phase of gait cycle, latter half of swing - eccentric contraction in preparation for foot contact. Biceps femoris stretch the most.
What stretch values do the hamstring muscles undergo?biceps femoris = 110%, semimembranosus = 107.5%, semiteninosus = 108.2%. Can be even longer in hurdles when maximum knee extension plus hip flexion occurs simultaneously.
List some intrinsic risk factors of hamstring strainPrevious injury, lack of flexibility. older age, core stability, ethnicity.
List some extrinsic factors of hamstring injuryinadequate warm up, fatigue, dehydration
Why could the biceps femoris aponeurosis be a risk factor?If the aponeurosis is small, mechanical strain is concentrated to a small cross sectional area. Size of apon. not related to muscle strength or size.
What are the signs and symptoms of hamstring strain?Sprinting > limping > slow down > stop > maybe fall. Localised stiffness, discolouration, swelling, bruising, redness. Inability to walk smoothly, discomfort with sitting
What is present upon physical examination of a hamstring strain?Stiff legged gait - avoidance of simultaneous hip flexion and knee extension. Ecchymosis.
What is the Puranen- Orava test?Patient stands with hip flexed and knee fully extended, heel on a support eg bed. Increasing posterior thigh pain indicates possible strain or tendinopathy
What is the bent knee stretch test?Patient lies supine on bed, hip and knee maximally flexed. Examiner slowly passively extends the knee, increasing posterior thigh pain with extension indicates strain or tendinopathy
What imaging is best for hamstring strain?Dynamic ultrasonography, fluid collections around injured muscle (oedema and or haemorrhage). MRI, defined injury location and degree of damage.
What does an isokinetic dynamometer test measure?Torque max generated by hamstring, quads, and their ratio (H/Q).
What H/Q ratios are there?concentric H to concentric Q (conventional). eccentric H to concentric Q (functional). concentric H to eccentric Q and eccentric to eccentric.
Why is the functional ratio usually used to represent knee/hamstring strength?Hamstring is usually lengthened when working (eccentric) so most accurate representation.
What should the H/Q functional ratio ideally be?at least 60% but ideally 75%
When is surgery indicated for hamstring strain?If the hamstring is completely torn
What is the rehab process after hamstring repair surgery?Aspiring for four weeks. day 10-14 - toe-touch weight bearing with crutches. week 2-5 25% weight bearing. passive exercise (week 2) and then active exercise (week4). Week 6, full weightbearing, isotonic exercise. Week 8 - dynamic training. week 10 - isometric strength eval with knee at 60% flexion. Week 12 - sport specific training. full return allowed when leg is at 80% of non-operative leg on isokinetic testing.
What are the NHS guidelines after hamstring tear?No pain - regular hamstring stretches. gentle exercise eg walking and cycling. do buttock stretch after exercise.
What is the "Supine bent knee walk out" exercise?bridge position, progressively move feet away from hips whilst maintaining a bridge. depends on patient tolerance and improvement. Strengthens Hamstrings
What is the "Supine single-limb chair-bridge" exercise?One leg on stationary raised object. raise hips and pelvis off ground leaving only upper back in contact with ground. Eccentric hamstring strengthening, should only be doen by patient impending return to sport
What is the "Single-limb balance windmill touches with dumbbells" exercise?stand on one leg with dumbbells overhead. perform windmill motion under control. end with dumbbell near floor.

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